Pressure-gage



l(No Mgdel.) 3 Sheets-Sheet 1.

C. B. BOSWORTH 8v J. H. MILLETT.

PRESSURE GAGE.

3 Sheets-Sheet 2.

C. B. BOSWORTH 8v J. H. MILLETT. PRESSURE GAGE.

No. 596,674. Patented Jen. 4, 1898.

(No Model.)

3 She ets-Sheet 8.

Patented Jan. 4

VK/ENTE@- Yffwa@ @um C. B. BOSWORTH 8v J. H. lVIILLETT.v

PRESSURE GAGE.

W1 TNI-:5555

. me News Pvrzns co.. pHoro-uw wmncr n c UNITED STATES PATENT OFFICE.

CHARLESv BARTLETT BOSVORTH, OF EVERETT, AND JOSHUA HOXVARD MIL- LETT, OF MALDEN, MASSACHUSETTS, ASSIGNORS TO THE CROSBY STEAM GAGE AND VALVE COMPANY, OF BOSTON, MASSACHUSETTS.

PRESSURE-GAG E.

SPECIFICATION forming part of Letters Patent No. 596,674, dated January 4,1898. Application iled January 24, 1896. Serial No. 576,679. (No model.)

To all whom it may concern.-

Be it known that we, CHARLES BARTLETT BosWoR'rH, residing at Everett, and JOSHUA HOWARD MILLETT, residing at Malden, in the county of Middlesex, State of Massachusetts, citizens of the United States, have invented certain new and useful Improvements in Pressure- Gages and we do hereby declare the following to be a full, clear, and exact ldescriplo tion of the invention, such as will enable 0thers skilled in the art to which it appertains to make and use the same.

This invention relates to an improvement in pressure-gages. More especially does it relate to that classof gages in whicha Bourdon tube is employed.

In the annexed drawings, Figure 1 represent-s' the invention located within the ordinary steamfgage case, having a portion of the 2o ring and dial removed in order to show the internal construction., part being in section.

Fig. 2 represents a cross-section through Fig.

l on the line 2 2. Fig. 3 represents in perspective view the water-chamberwith certain 2 5 portions broken away at the boss which connects it to the boiler. Fig. 4 represents in perspective View the Bourdon spring. Fig.

5 represents a similar view to Fig. 1,but showing a modification.

3o In the drawings the letter A represents an` ordinary pressure-gage case, within which is placed the operative mechanism of the gage. IVithin this case is placed a Water chamber B. This water-chamber is made substantially 3 5 ellipsoidal in shape and has a partition b. At this partition b the chamber B is provided at one side with a threaded projection or boss b'. This projection b' protru'des through a hole in the back of the case A and is for the 4o purpose f connecting the steam-pipe of the boiler or other receptacle to which the pressure-gage is attached. This boss b' has a hollow bore b2, from which a passage b3 leads to the interior of the Water-chamber B on one side of the partition b.

` Surrounding the waterchamber B is the usual Bourdon spring'C, a projection b4 hold- -ing the two snugly together'.- On the side of the partition b away from the passage bB an- ,v 5o other, passage b5 opens from the interior of ply them.

the water-chamber B into the interior of the Bourdon spring, as at c, and a passage c' leads from the interior of the Bourdon spring through the boss or projection b. To the protuberances a a' a the dial D,With its g- 55 ures, is connected, and to the projections or lugs 0L2 the sector mechanism for conveying the movement of the tube-springs is attached.l

AAs the present invention has no relation to the precise form of this latter mechanism and 6o any form will serve in connection with the parts described to exemplify the invention, a detailed description of such mechanism is not regarded as necessary.

By this construction the whole interior part 6 5 of the gage is borne upon and becomes an integral part of the Water-chamber B and is entirely independent of the case in which it may be located,except at the point of attachment of the screws a3 a?, where it is securedto the 7o back of the case. By this means the gage is not disturbed or in [iuenced in any degree `by any action of .the case due to the change of temperature. j

With this construction the iiuid will enter the bore b2 of the boss b' and pass through the passage b3 into the water-chamber B on one side of the partition b, thence around the water-chamber to the other side of the partition b, thence through the passage lf into 8o the interior of the Bourdon spring C, and thence through the passage c', the waterchamber having filled with the iuid.

In a construction such as described there is formed within the inner circle of the tubesprings a water-chamber of sufficien t capacity and character that it will supply not only in the largest degree the tube -springs with water to protect them, but also tends to reduce the temperature about them when subjected to 9o great heat. -v

All steam-pressure gages arc required to have their Bourdon springs protected from the heat to which they may be subjected in use by some device containing water to sup- This is ordinarily done by what is called a ,siphon, generally consisting of va bent tube, and is located outside of and below thegage. In most cases this Siphon is of such capacit-y as to afford but little benefit zoo to the gage. Its importance lies in the fact that when the tube-springs are subjected to a temperaturevgreater than that required to generate Water into steam in use under pressure they will be upset or permanently change their form, so .that they become inaccurate and unsafe. This occurs always when steam is admitted directly into the tube-springs of the gage, which often takes place from neglect `in not filling the. siphon, or from the small capacity of the Siphon, o r from the factV that the Siphon is subjected to such heat asv to convert the water in it' into steam. It is therefore'necessary for absolute-protection to steam-gages where they are used in high temperatures that there be such a quantity of Water as shall fully supply the tube-springs under all conditions, and it shall not be easily converted into steam by any heat which may be .conveyed to it by any connection .which the steam-gage may have to the boiler, It is' be converted into steam by the connection of heat due to its attachment to the .boil er; third, that all the operative parts of the gage and those which are liable to disturbances by a variable temperature, as by their expansion4 or contraction, are mounted uponthis waterchamber of a comparatively uniform temperature and thus are aected or controlled to a very large extent by it. n

Fig. 5 shows a modification of this device.

In thisform the connection of the waterchamber B is downward through the gagecase, as shown at b4.l This passage runs directly from the open air, where it is attached to a steam-boiler. The outlet from the chamber onthe other side of the partition b is by the passage b5 into the Bourdon tube and thence outward to the open air. This passage is closed by va screwb. This form is simpler than that shown by the other iigures. Inthis one, by inverting the gage so that the ope'ning into the passage b4. shall be uppermost, the water may be poured into such passage, thence passing into the Water-chamber, and outward by the passage b5,\into the Bour; don tube-C, and Vagain outward to the open air, where it'will appear whenthe'passages and chamber are full, the screwy closing the passageb5 having been removed. Then upon replacing the screw b 'the gage is ready for service.

Having described our invention, what we claiml is` A 1. In a pressure-gage the combination of a Bourdon' spring with a water-chamber entirely located within the curve of the spring, as set forth.

` 2. In a pressure-gage the combination ofthe Water-chamber and a Bourdon spring arranged one within the other and having a Water-passage connecting the two', the Waterchamber being provided with a boss or extension, such boss being provided with a pas sage leading into the `Water-chamber anda passagel leading from the Bourdon tube, as`

CHARLES BARTLETTl yBOSWOR'IH. JOSHUA HOWARD lllIlrhE'lT.

Witnesses:

ARTHUR L. BOWKER, OMAR H. GIBBS. 

